abstract
A mild synthesis of 3,5-disubstituted nitrobenzenes from readily available 3-formylchromones is reported. The developed methodology follows a cascade process, promoted by 1,8-diazabicyclo[5.4.0]undec-7-ene. The proposed mechanism involves an initial Michael addition of nitromethane at C-2 of a 3-formylchromone. The resultant intermediate undergoes another Michael reaction with a second 3-formylchromone molecule. After ring closure through intramolecular cyclization, the aromatization is completed by deformylation, affording the 3,5-disubstituted nitrobenzenes in 52-86% yield. The reported method produces three new C-C bonds in a simple and straightforward manner, and it is consistent with gram-scale synthesis.
keywords
OXIDATION
subject category
Chemistry
authors
Francisco, TN; Sousa, JLC; Guieu, S; Silva, AMS; Albuquerque, HMT
our authors
Joana Lia Cardoso de Sousa
Post-Doc Fellowship
Samuel Jacques André Guieu
Junior Researcheracknowledgements
This work was financed by Portugal 2020 through FEDER in the framework of POCI and in the scope of the projects EpigenGlicON (POCI-01-0145-FEDER-029767), LAQV-REQUIMTE (UIDB/50006/2020), and CICECO -Aveiro Institute of Materials (UIDB/50011/2020 & UIDP/50011/2020), co-financed by FCT/MCTES. J.S., H.A., and T.F. acknowledge the EpigenGlicON project (POCI-01-0145-FEDER029767) for their researcher contracts and research grant, respectively.